There are a number of small vehicles which preferably should have “automatic” transmissions for ease of driving and for increased utility. These include ATV's, tractors, utility vehicles and small automobiles. These vehicles are generally in the 25 HP to 50 HP range, and have common requirements for low cost, high efficiency, good controllability and short length. Many vehicles require through power from the engine out the back of the transmission; many vehicles require drive to both front and rear axles. Some of these vehicles currently integrate the engine and transmission into a single package.
However, there can be a wide range in the required transmission ratio spread which varies by vehicle vocation. Further, the transmission configuration varies with the specific vehicle design. Both of these issues can be major determinants of cost. There are some differences in engine speed, which can affect the sizing of the transmission components. In consideration of these variations, the individual vehicle volumes are generally not enough to support low cost manufacturing.
It is therefore a principal object of this invention to provide a small engine transmission which has the ability to change all gears ratios in order to accommodate various input speeds, output speeds and ratio spread requirements.
A further object of the invention is to provide a small engine transmission which has a transmission configuration which allows for through power transmission from the engine to the opposite end of the transmission and for through power transmission of the output shaft to either or both ends.
A still further object of this invention is to provide a small vehicle transmission that has a transmission configuration which has a center housing portion which contains features and location for two hydrostatic units including shafts and drive gears, the hydraulic reservoir and one set of clutch shift means, and which is common across the range of transmission applications.
A still further object of this invention is to provide a small vehicle transmission which allows for integration and common usage of one or more engine/transmission features including gears, hydraulic pump, housing and/or controller.
These and other objects will be apparent to those skilled in the art.